Lacazette put the Gunners ahead early in the first-half only for Sead Kolasinac to gift an equaliser to Spurs just three minutes later.
"Really disappointed because I think we could do better," said Lacazette after the game.
"We gave a lot today but as the coach said, with [small] details a big game can change. It happened today."
On his spectacular long-range goal, the Frenchman was equally as frank.
"It was a great goal but at the end we don't win, so it's nothing at the end."